scholarly journals Inhibition of De Novo Pyrimidine Synthesis Depletes Acute Myleogenous Leukemia Stem Cells (LSCs) Burden and Triggers Apoptosis and Differentiation Associated with Oxidative Stress

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2249-2249
Author(s):  
Sujan Piya ◽  
Huaxian Ma ◽  
Priyanka Sharma ◽  
Kensuke Kojima ◽  
Vivian Ruvolo ◽  
...  

Abstract Background: De novo nucleotide synthesis is necessary to meet the enormous demand for nucleotides, other macromolecules associated with acute myeloid leukemia (AML) progression 1, 2, 3 4. Hence, we hypothesized that targeting de novo nucleotide synthesis would lead to the depletion of the nucleotide pool, pyrimidine starvation and increase oxidative stress preferentially in leukemic cells compared to their non-malignant counterparts, impacting proliferative and differentiation pathways. Emvododstat (PTC299) is an inhibitor of dihydroorotate dehydrogenase (DHODH), a rate-limiting enzyme for de novo pyrimidine nucleotide synthesis that is currently in a clinical trial for the treatment of AML. Objectives: The goals of these studies were to understand the emvododstat-mediated effects on leukemia growth, differentiation and impact on Leukemia Stem Cells(LSCs). Comprehensive analyses of mitochondrial function, metabolic signaling in PI3K/AKT pathways, apoptotic signatures, and DNA damage responses were carried out. The rationale for clinical testing emvododstat was confirmed in an AML-PDX model. Results: Emvododstat treatment in cytarabine-resistant AML cells and primary AML blasts induced apoptosis, differentiation, and reduced proliferation, with corresponding decreased in cell number and increases in annexin V- and CD14-positive cells. Indeed, the inhibition of de novo nucleotide synthesis compromises the dynamic metabolic landscape and mitochondrial function, as indicated by alterations in the oxygen consumption rate (OCR) and mitochondrial ROS/membrane potential and corresponding differentiation, apoptosis, and/or inhibition of proliferation of LSCs. These effects can be reversed by the addition of exogenous uridine and orotate. Further immunoblotting and mass cytometry (CyTOF) analyses demonstrated changes in apoptotic and cell signaling proteins (cleaved PARP, cleaved caspase-3) and DNA damage responses (TP53, γH2AX) and PI3/AKT pathway downregulation in response to emvododstat. Importantly, emvododstat treatment reduced leukemic cell burden in a mouse model of AML PDX ( Complex karyotype ,mutation in ASXL1, IDH2, NRAS), decreased levels of leukemia stem cells frequency (1 in 522,460 Vs 1 in 3,623,599 in vehicle vs emvododstat treated mice), and improved survival. The median survival 40 days vs. 30 days, P=0.0002 in primary transplantation and 36 days vs 53.5 days, P=0.005 in secondary transpantation in a PDX mouse model of human AML. This corresponded with a reduction in the bone marrow burden of leukemia and increased expression of differentiation markers in mice treated with emvododstat (Fig. 1). These data demonstrate effect of emvododstat on mitochondrial functions . Conclusion: Inhibition of de novo pyrimidine synthesis triggers differentiation, apoptosis, and depletes LSCs in AML models. Emvododstat is a novel dihydroorotate dehydrogenase inhibitor being tested in a clinical trial for the treatment of myeloid malignancies and COVID-19. Keywords: AML, emvododstat, DHODH, apoptosis, differentiation References: 1 Thomas, D. & Majeti, R. Biology and relevance of human acute myeloid leukemia stem cells. Blood 129, 1577-1585, doi:10.1182/blood-2016-10-696054 (2017). 2 Quek, L. et al. Genetically distinct leukemic stem cells in human CD34- acute myeloid leukemia are arrested at a hemopoietic precursor-like stage. The Journal of experimental medicine 213, 1513-1535, doi:10.1084/jem.20151775 (2016). 3 Villa, E., Ali, E. S., Sahu, U. & Ben-Sahra, I. Cancer Cells Tune the Signaling Pathways to Empower de Novo Synthesis of Nucleotides. Cancers (Basel) 11, doi:10.3390/cancers11050688 (2019). 4 DeBerardinis, R. J. & Chandel, N. S. Fundamentals of cancer metabolism. Sci Adv 2, e1600200, doi:10.1126/sciadv.1600200 (2016). Figure 1 Figure 1. Disclosures Weetall: PTC therapeutics: Current Employment. Sheedy: PTC therapeutics: Current Employment. Ray: PTC therapeutics: Current Employment. Andreeff: Karyopharm: Research Funding; AstraZeneca: Research Funding; Oxford Biomedica UK: Research Funding; Aptose: Consultancy; Daiichi-Sankyo: Consultancy, Research Funding; Syndax: Consultancy; Breast Cancer Research Foundation: Research Funding; Reata, Aptose, Eutropics, SentiBio; Chimerix, Oncolyze: Current holder of individual stocks in a privately-held company; Novartis, Cancer UK; Leukemia & Lymphoma Society (LLS), German Research Council; NCI-RDCRN (Rare Disease Clin Network), CLL Foundation; Novartis: Membership on an entity's Board of Directors or advisory committees; Senti-Bio: Consultancy; Medicxi: Consultancy; ONO Pharmaceuticals: Research Funding; Amgen: Research Funding; Glycomimetics: Consultancy. Borthakur: ArgenX: Membership on an entity's Board of Directors or advisory committees; Protagonist: Consultancy; Astex: Research Funding; University of Texas MD Anderson Cancer Center: Current Employment; Ryvu: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy.

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3402-3402
Author(s):  
Seung-Ah Yahng ◽  
Jae-Ho Yoon ◽  
Sung-Eun Lee ◽  
Seung-Hwan Shin ◽  
Byung-Sik Cho ◽  
...  

Abstract Background The successful induction chemotherapy of acute myeloid leukemia (AML) depends on the ability to achieve complete remission (CR) and to maintain remission status as long as possible. Approach to improve the rate of CR includes the intensification of induction chemotherapy for AML. The primary goal of this study was to evaluate and compare the long-term outcomes between remission induction therapy with and without early intensification added to the standard 3+7 remission induction regimen. Methods A retrospective analysis was performed on de novo AML patients diagnosed and treated at Catholic Blood and Marrow Transplantation Center between January 2001 and December 2010. Six hundred forty-one adults of ages between 16 and 60 were included, all of whom received induction chemotherapy starting with 3 days of idarubicin and 7 days of cytarabine or behenoyl cytarabine (BHAC). Cases with t(9;22) and t(15;17) were excluded. Bone marrow (BM) aspiration study was assessed on day 7 of induction in all patients. Factors which were considered for early intensification of induction were the presence of ≥ 5% BM blasts, patient performance, and other high risk clinical characteristics, such as karyotype. Groups according to early intensification on days 8 to 10 of induction were as followings: no intensification (3+7), n=156; cytarabine or BHAC for 3 days (3+10), n=233; addition of idarubicin for 2 days to 3+10 regimen (5+10), n=252. After a median duration of 5.5 months (3.3-19.0) from diagnosis, 479 patients underwent stem cell transplantation (autologous [auto-SCT], n=144; allogeneic [allo-SCT], n=335). Conditioning regimen for auto-SCT consisted of fractionated total body irradiation (TBI), melphalan, and cytarabine, whereas 83% (n=278) of patients with allo-SCT received myeloablative conditioning, of which was mostly TBI-based regimen (92%). Donors were matched sibling (n=213), matched unrelated (n=63), mismatched unrelated (n=39), and haploidentical related (n=20). Results The median age at diagnosis was 39 years (16-60). Mean values of BM blast % on day 7 of induction was 3.5 in 3+7 group, 7.9 in 3+10, and 33.6 in 5+10 (p=<0.0001), while no significant difference in the proportion of adverse karyotype was shown (11.7% vs. 12.8%, p=0.804). After first induction (3+7, n=165; 3+10/5+10, n=465), the CR/CRi rate was significantly higher in 3+10/5+10 versus 3+7 (78.1% vs. 69.2%, p=0.023), while the rate for death in aplasia was lower (4.3% vs. 9.6%, p=0.013). After re-induction with various regimens, the CR/CRi rate was still significantly higher in intensified group (p=0.012). The relapse rates between the groups in 536 patients achieving CR (83.6%), however, was not significantly different (8.9% vs. 9.9%, p=0.737). SCT was performed at CR1 (n=459), CR2 (n=10), or relapsed/refractory status (n=10). Patients with auto-SCT mostly had better/intermediate cytogenetic risk (96%) at diagnosis, while 12% of allo-SCT had poor karyotype. After the median follow-up duration of 60.2 months (2.2-143.5), the median overall survival (OS) in all patients (n=641) was 65.6 months. The 5-year disease-free survival (DFS) of patients with auto- and allo-SCT was 58.4±4.2 and 64.9±2.7, respectively. Of 334 patients receiving allo-SCT, the 5-year DFS was significantly higher in patients achieving CR1 (n=299) after first induction therapy (p<0.0001), in whom 75% of them had early intensification. Other factors with significant impact on DFS after allo-SCT (n=334) were karyotype at diagnosis (p=0.032) and donor type (HLA-matched vs. HLA-mismatched sibling or unrelated, 58.1%±3.8 vs. 45.1±8.0, p=0.016). The significances were confirmed in multivariate analysis, which demonstrated that achieving CR1 after first induction regimen and its maintenance until SCT was the most powerful predictor for DFS after allo-SCT (67.1±2.9 vs. 34.6±7.8, p=<0.0001). When all patients were analyzed, according to induction intensification, a statistically significant benefit in 10-year OS was observed in 5+10 intensified group (44.8% vs. 52.9%, p=0.032). Conclusion Our results suggest possible benefit of examining day 7 BM aspiration for the strategy of early intensification of induction chemotherapy for adult AML patients and our intensification doses can be safely added with high efficacy in the achievement of CR1 compared to 3+7 standard regimen, and may have affected for better DFS after allo-SCT. Disclosures: Kim: BMS: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 7-8
Author(s):  
Philip C. Amrein ◽  
Eyal C. Attar ◽  
Geoffrey Fell ◽  
Traci M. Blonquist ◽  
Andrew M. Brunner ◽  
...  

Introduction: Outcomes for acute myeloid leukemia (AML) among older patients has remained largely unchanged for decades. Long-term survival for patients aged &gt;60 years is poor (median survival 10.5 months). Targeting the proteasome in AML is attractive, since leukemia stem cells have demonstrated sensitivity to proteasome inhibition in preclinical models, perhaps through down regulation of nuclear NF-KB (Guzman, Blood 2001). AML cell lines are susceptible to synergistic cytotoxicity when bortezomib, a proteasome inhibitor, is combined with daunorubicin and cytarabine. We have shown that adding bortezomib to standard treatment in AML results in a high remission rate, although grade 2 sensory neurotoxicity was noted in approximately 12% of treated patients. A newer generation proteasome inhibitor, ixazomib, is less frequently associated with neurotoxicity, and, therefore, was selected for combination with conventional chemotherapy in this phase I trial. The primary objective of this study was to determine the maximum tolerated dose (MTD) of ixazomib in combination with conventional induction and consolidation chemotherapy for AML. Herein are the initial results of this trial. Methods: Adults &gt;60 years of age with newly diagnosed AML were screened for eligibility. Patients with secondary AML were eligible, including those with prior hypomethylating agent therapy for myelodysplastic syndromes (MDS). We excluded those with promyelocytic leukemia. There were 2 phases in this study. In the first phase (A), the induction treatment consisted of the following: cytarabine 100 mg/m2/day by continuous IV infusion, Days 1-7; daunorubicin 60 mg/m2/day IV, Days 1, 2, 3, and ixazomib was provided orally at the cohort dose, Days 2, 5, 9, and 12. Consolidaton or transplant was at the discretion of the treating physician in phase A. In the second phase (B), induction was the same as that with the determined MTD of ixazomib. All patients were to be treated with the following consolidation: cytarabine at 2 g/m2/day, days 1-5 with ixazomib on days 2, 5, 9, and 12 at the cohort dose for consolidation. A standard 3 + 3 patient cohort dose escalation design was used to determine whether the dose of ixazomib could be safely escalated in 3 cohorts (1.5 mg/day, 2.3 mg/day, 3.0 mg/day), initially in induction (phase A) and subsequently in consolidation (phase B). The determined MTD of ixazomib in the first portion (A) of the trial was used during induction in the second portion (B), which sought to determine the MTD for ixazomib during consolidation. Secondary objectives included rate of complete remission, disease-free survival, and overall survival (OS). Results: Thirty-six patients have been enrolled on study, and 28 have completed dose levels A-1 through A-3 and B1 through B-2. Full information on cohort B-3 has not yet been obtained, hence, this report covers the experience with the initial 28 patients, cohorts A-1 through B-2. There were 12 (43%) patients among the 28 with secondary AML, either with prior hematologic malignancy or therapy-related AML. Nineteen patients (68%) were male, and the median age was 68 years (range 61-80 years). There have been no grade 5 toxicities due to study drug. Three patients died early due to leukemia, 2 of which were replaced for assessment of the MTD. Nearly all the grade 3 and 4 toxicities were hematologic (Table). There was 1 DLT (grade 4 platelet count decrease extending beyond Day 42). There has been no grade 3 or 4 neurotoxicity with ixazomib to date. Among the 28 patients in the first 5 cohorts, 22 achieved complete remissions (CR) and 2 achieved CRi, for a composite remission rate (CCR) of 86%. Among the 12 patients with secondary AML 8 achieved CR and 2 achieved CRi, for a CCR of 83%. The median OS for the 28 patients has not been reached (graph). The 18-month OS estimate was 65% [90% CI, 50-85%]. Conclusions: The highest dose level (3 mg) of ixazomib planned for induction in this trial has been reached safely. For consolidation there have been no serious safety issues in the first 2 cohorts with a dose up to 2.3 mg, apart from 1 DLT in the form of delayed platelet count recovery. The recommended phase 2 dose of ixazomib for induction is 3 mg. Accrual to cohort B-3 is ongoing. Notably, to date, no grade 3 or 4 neurotoxicity has been encountered. The remission rate in this older adult population with the addition of ixazomib to standard chemotherapy appears favorable. Figure Disclosures Amrein: Amgen: Research Funding; AstraZeneca: Consultancy, Research Funding; Takeda: Research Funding. Attar:Aprea Therapeutics: Current Employment. Brunner:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Forty-Seven Inc: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Research Funding; Takeda: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding. Hobbs:Constellation: Honoraria, Research Funding; Novartis: Honoraria; Incyte: Research Funding; Merck: Research Funding; Bayer: Research Funding; Jazz: Honoraria; Celgene/BMS: Honoraria. Neuberg:Celgene: Research Funding; Madrigak Pharmaceuticals: Current equity holder in publicly-traded company; Pharmacyclics: Research Funding. Fathi:Blueprint: Consultancy; Boston Biomedical: Consultancy; BMS/Celgene: Consultancy, Research Funding; Novartis: Consultancy; Kura Oncology: Consultancy; Trillium: Consultancy; Amgen: Consultancy; Seattle Genetics: Consultancy, Research Funding; Abbvie: Consultancy; Pfizer: Consultancy; Newlink Genetics: Consultancy; Forty Seven: Consultancy; Trovagene: Consultancy; Kite: Consultancy; Daiichi Sankyo: Consultancy; Astellas: Consultancy; Amphivena: Consultancy; PTC Therapeutics: Consultancy; Agios: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Jazz: Consultancy. OffLabel Disclosure: Ixazomib is FDA approved for multiple myeloma. We are using it in this trial for acute myeloid leukemia.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 8-9
Author(s):  
Sujan Piya ◽  
Marla Weetall ◽  
Josephine Sheedy ◽  
Balmiki Ray ◽  
Huaxian Ma ◽  
...  

Introduction: Acute myeloid leukemia (AML) is characterized by both aberrant proliferation and differentiation arrest at hematopoietic progenitor stages 1,2. AML relies upon de novo nucleotide synthesis to meet a dynamic metabolic landscape and to provide a sufficient supply of nucleotides and other macromolecules 3,4. Hence, we hypothesized that inhibition of de novo nucleotide synthesis would lead to depletion of the nucleotide pool and pyrimidine starvation in leukemic cells compared to their non-malignant counterparts and impact proliferative and differentiation inhibition pathways. PTC299 is an inhibitor of dihydroorotate dehydrogenase (DHODH), a rate limiting enzyme for de novo pyrimidine nucleotide synthesis that is currently in a clinical trial for the treatment of AML. Aim: We investigated the pre-clinical activity of PTC299 against AML in primary AML blasts and cytarabine-resistant cell lines. To confirm that PTC299 effects are due to inhibition of de novo pyrimidine nucleotide synthesis for leukemic growth, we specifically tested the impact of uridine and orotate rescue. In addition, a comprehensive analysis of alteration of metabolic signaling in PI3K/AKT pathways, apoptotic signatures and DNA damage responses were analyzed by Mass cytometry based proteomic analysis (CyTOF) and immunoblotting. The potential clinical relevance of DHODH inhibition was confirmed in an AML-PDX model. Results: The IC50s for all tested cell lines (at 3 day) and primary blasts (at 5-7 day) were in a very low nanomolar range: OCI-AML3 -4.43 nM, HL60 -59.7 nM and primary samples -18-90 nM. Treatment of AML in cytarabine-resistant cells demonstrated that PTC299 induced apoptosis, differentiation, and reduced proliferation with corresponding increase in Annexin V and CD14 positive cells (Fig.1). PTC299-induced apoptosis and inhibition of proliferation was rescued by uridine and orotate. To gain more mechanistic insights, we used an immunoblotting and mass cytometry (CyTOF) based approach to analyze changes in apoptotic and cell signaling proteins in OCI-AML3 cells. Apoptotic pathways were induced (cleaved PARP, cleaved Caspase-3) and DNA damage responses (TP53, γH2AX) and the PI3/AKT pathway were downregulated in response to PTC299. In isogenic cell lines, p53-wildtype cells were sustained and an increased DNA damage response with corresponding increase in apoptosis in comparison to p53-deficient cells was shown. (Fig.2) In a PDX mouse model of human AML, PTC299 treatment improved survival compared to mice treated with vehicle (median survival 40 days vs. 30 days, P=0.0002) (Fig.3). This corresponded with a reduction in the bone marrow burden of leukemia with increased expression of differentiation markers in mice treated with PTC299 (Fig.3). Conclusion: PTC299 is a novel dihydroorotate dehydrogenase (DHODH) inhibitor that triggers differentiation, apoptosis and/or inhibition of proliferation in AML and is being tested in a clinical trials for the treatment of acute myeloid malignancies. Reference: 1. Thomas D, Majeti R. Biology and relevance of human acute myeloid leukemia stem cells. Blood 2017; 129(12): 1577-1585. e-pub ahead of print 2017/02/06; doi: 10.1182/blood-2016-10-696054 2. Quek L, Otto GW, Garnett C, Lhermitte L, Karamitros D, Stoilova B et al. Genetically distinct leukemic stem cells in human CD34- acute myeloid leukemia are arrested at a hemopoietic precursor-like stage. The Journal of experimental medicine 2016; 213(8): 1513-1535. e-pub ahead of print 2016/07/06; doi: 10.1084/jem.20151775 3. Villa E, Ali ES, Sahu U, Ben-Sahra I. Cancer Cells Tune the Signaling Pathways to Empower de Novo Synthesis of Nucleotides. Cancers (Basel) 2019; 11(5). e-pub ahead of print 2019/05/22; doi: 10.3390/cancers11050688 4. DeBerardinis RJ, Chandel NS. Fundamentals of cancer metabolism. Sci Adv 2016; 2(5): e1600200. e-pub ahead of print 2016/07/08; doi: 10.1126/sciadv.1600200 Disclosures Weetall: PTC Therapeutic: Current Employment. Sheedy:PTC therapeutics: Current Employment. Ray:PTC Therapeutics Inc.: Current Employment. Konopleva:Genentech: Consultancy, Research Funding; Rafael Pharmaceutical: Research Funding; Ablynx: Research Funding; Ascentage: Research Funding; Agios: Research Funding; Kisoji: Consultancy; Eli Lilly: Research Funding; AstraZeneca: Research Funding; Reata Pharmaceutical Inc.;: Patents & Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; AbbVie: Consultancy, Research Funding; Calithera: Research Funding; Cellectis: Research Funding; Amgen: Consultancy; Stemline Therapeutics: Consultancy, Research Funding; Forty-Seven: Consultancy, Research Funding; F. Hoffmann La-Roche: Consultancy, Research Funding; Sanofi: Research Funding. Andreeff:Amgen: Research Funding; Daiichi-Sankyo; Jazz Pharmaceuticals; Celgene; Amgen; AstraZeneca; 6 Dimensions Capital: Consultancy; Daiichi-Sankyo; Breast Cancer Research Foundation; CPRIT; NIH/NCI; Amgen; AstraZeneca: Research Funding; Centre for Drug Research & Development; Cancer UK; NCI-CTEP; German Research Council; Leukemia Lymphoma Foundation (LLS); NCI-RDCRN (Rare Disease Clin Network); CLL Founcdation; BioLineRx; SentiBio; Aptose Biosciences, Inc: Membership on an entity's Board of Directors or advisory committees. Borthakur:BioLine Rx: Consultancy; BioTherix: Consultancy; Nkarta Therapeutics: Consultancy; Treadwell Therapeutics: Consultancy; Xbiotech USA: Research Funding; Polaris: Research Funding; AstraZeneca: Research Funding; BMS: Research Funding; BioLine Rx: Research Funding; Cyclacel: Research Funding; GSK: Research Funding; Jannsen: Research Funding; Abbvie: Research Funding; Novartis: Research Funding; Incyte: Research Funding; PTC Therapeutics: Research Funding; FTC Therapeutics: Consultancy; Curio Science LLC: Consultancy; PTC Therapeutics: Consultancy; Argenx: Consultancy; Oncoceutics: Research Funding.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1528-1528
Author(s):  
Sebastian Stasik ◽  
Jan Moritz Middeke ◽  
Michael Kramer ◽  
Christoph Rollig ◽  
Alwin Krämer ◽  
...  

Abstract Purpose: The enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase and key epigenetic regulator involved in transcriptional repression and embryonic development. Loss of EZH2 activity by inactivating mutations is associated with poor prognosis in myeloid malignancies such as MDS. More recently, EZH2 inactivation was shown to induce chemoresistance in acute myeloid leukemia (AML) (Göllner et al., 2017). Data on the frequency and prognostic role of EZH2-mutations in AML are rare and mostly confined to smaller cohorts. To investigate the prevalence and prognostic impact of this alteration in more detail, we analyzed a large cohort of AML patients (n = 1604) for EZH2 mutations. Patients and Methods: All patients analyzed had newly diagnosed AML, were registered in clinical protocols of the Study Alliance Leukemia (SAL) (AML96, AML2003 or AML60+, SORAML) and had available material at diagnosis. Screening for EZH2 mutations and associated alterations was done using Next-Generation Sequencing (NGS) (TruSight Myeloid Sequencing Panel, Illumina) on an Illumina MiSeq-system using bone marrow or peripheral blood. Detection was conducted with a defined cut-off of 5% variant allele frequency (VAF). All samples below the predefined threshold were classified as EZH2 wild type (wt). Patient clinical characteristics and co-mutations were analyzed according to the mutational status. Furthermore, multivariate analysis was used to identify the impact of EZH2 mutations on outcome. Results: EZH2-mutations were found in 63 of 1604 (4%) patients, with a median VAF of 44% (range 6-97%; median coverage 3077x). Mutations were detected within several exons (2-6; 8-12; 14-20) with highest frequencies in exons 17 and 18 (29%). The majority of detected mutations (71% missense and 29% nonsense/frameshift) were single nucleotide variants (SNVs) (87%), followed by small indel mutations. Descriptive statistics of clinical parameters and associated co-mutations revealed significant differences between EZH2-mut and -wt patients. At diagnosis, patients with EZH2 mutations were significantly older (median age 59 yrs) than EZH2-wt patients (median 56 yrs; p=0.044). In addition, significantly fewer EZH2-mut patients (71%) were diagnosed with de novo AML compared to EZH2-wt patients (84%; p=0.036). Accordingly, EZH2-mut patients had a higher rate of secondary acute myeloid leukemia (sAML) (21%), evolving from prior MDS or after prior chemotherapy (tAML) (8%; p=0.036). Also, bone marrow (and blood) blast counts differed between the two groups (EZH2-mut patients had significantly lower BM and PB blast counts; p=0.013). In contrast, no differences were observed for WBC counts, karyotype, ECOG performance status and ELN-2017 risk category compared to EZH2-wt patients. Based on cytogenetics according to the 2017 ELN criteria, 35% of EZH2-mut patients were categorized with favorable risk, 28% had intermediate and 37% adverse risk. No association was seen with -7/7q-. In the group of EZH2-mut AML patients, significantly higher rates of co-mutations were detected in RUNX1 (25%), ASXL1 (22%) and NRAS (25%) compared to EZH2-wt patients (with 10%; 8% and 15%, respectively). Vice versa, concomitant mutations in NPM1 were (non-significantly) more common in EZH2-wt patients (33%) vs EZH2-mut patients (21%). For other frequently mutated genes in AML there was no major difference between EZH2-mut and -wt patients, e.g. FLT3ITD (13%), FLT3TKD (10%) and CEBPA (24%), as well as genes encoding epigenetic modifiers, namely, DNMT3A (21%), IDH1/2 (11/14%), and TET2 (21%). The correlation of EZH2 mutational status with clinical outcomes showed no effect of EZH2 mutations on the rate of complete remission (CR), relapse free survival (RFS) and overall survival (OS) (with a median OS of 18.4 and 17.1 months for EZH2-mut and -wt patients, respectively) in the univariate analyses. Likewise, the multivariate analysis with clinical variable such as age, cytogenetics and WBC using Cox proportional hazard regression, revealed that EZH2 mutations were not an independent risk factor for OS or RFS. Conclusion EZH mutations are recurrent alterations in patients with AML. The association with certain clinical factors and typical mutations such as RUNX1 and ASXL1 points to the fact that these mutations are associated with secondary AML. Our data do not indicate that EZH2 mutations represent an independent prognostic factor. Disclosures Middeke: Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. Rollig:Bayer: Research Funding; Janssen: Research Funding. Scholl:Jazz Pharma: Membership on an entity's Board of Directors or advisory committees; Abbivie: Other: Travel support; Alexion: Other: Travel support; MDS: Other: Travel support; Novartis: Other: Travel support; Deutsche Krebshilfe: Research Funding; Carreras Foundation: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees. Hochhaus:Pfizer: Research Funding; Incyte: Research Funding; Novartis: Research Funding; Bristol-Myers Squibb: Research Funding; Takeda: Research Funding. Brümmendorf:Janssen: Consultancy; Takeda: Consultancy; Novartis: Consultancy, Research Funding; Merck: Consultancy; Pfizer: Consultancy, Research Funding. Burchert:AOP Orphan: Honoraria, Research Funding; Bayer: Research Funding; Pfizer: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Novartis: Research Funding. Krause:Novartis: Research Funding. Hänel:Amgen: Honoraria; Roche: Honoraria; Takeda: Honoraria; Novartis: Honoraria. Platzbecker:Celgene: Research Funding. Mayer:Eisai: Research Funding; Novartis: Research Funding; Roche: Research Funding; Johnson & Johnson: Research Funding; Affimed: Research Funding. Serve:Bayer: Research Funding. Ehninger:Cellex Gesellschaft fuer Zellgewinnung mbH: Employment, Equity Ownership; Bayer: Research Funding; GEMoaB Monoclonals GmbH: Employment, Equity Ownership. Thiede:AgenDix: Other: Ownership; Novartis: Honoraria, Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 338-338
Author(s):  
Bradstock Kenneth ◽  
Emma Link ◽  
Juliana Di Iulio ◽  
Jeff Szer ◽  
Paula Marlton ◽  
...  

Abstract Background: Anthracylines are one of the major classes of drugs active against acute myeloid leukemia (AML). Increased doses of daunorubicin during induction therapy for AML have been shown to improve remission rates and survival. The ALLG used idarubicin in induction therapy at a dose of 9 mg/m2 x 3 days (total dose 27 mg/m2) in combination with high-dose cytarabine and etoposide (Blood 2005, 105:481), but showed that a total idarubicin dose of 36 mg/m2 was too toxic in this context (Leukemia 2001, 15:1331). In order to further improve outcomes in adult AML by anthracycline dose escalation, we conducted a phase 3 trial comparing standard to an increased idarubicin dose during consolidation therapy. Methods: Patients achieving complete remission after 1 or 2 cycles of intensive induction therapy (idarubicin 9 mg/m2 daily x3, cytarabine 3 g/m2 twice daily on days 1,3,5 and 7, and etoposide 75 mg/m2 daily x7; ICE protocol) were randomized to receive 2 cycles of consolidation therapy with cytarabine 100 mg/m2 per day for 5 days, etoposide 75 mg/m2 for 5 days, and idarubicin 9mg/m2 daily for either 2 or 3 days (standard and intensive arms respectively). No further protocol therapy was given. The primary endpoint was leukemia-free survival from randomization to consolidation therapy (LFS) with overall survival (OS) as secondary endpoint. Results: A total of 422 patients with AML (excluding cases with CBF rearrangements or APL) aged 16 to 60 years were enrolled between 2003-10, with 345 (82%) achieving complete remission, and 293 being randomized to standard (n=146) or intensive (n=147) consolidation arms. The median age was 45 years in both arms (range 16- 60), and both groups were balanced for intermediate versus unfavorable karyotypes and for frequency of mutations involving FLT3-ITD and NPM1 genes. Of the randomized patients, 120 in the standard arm (82%) and 95 in the intensive arm (65%) received the second consolidation cycle (p<0.001). The median total dose of idarubicin received in the 2 consolidation courses was 36 mg/m2 (range 17-45), or 99% (47-125%) of the protocol dose in the standard arm, versus 53 mg/m2 (18-73), or 98% (33-136%) of the protocol dose in the intensive arm. The durations of grades 3-4 neutropenia and thrombocytopenia were significantly longer in the intensive arm, but there were no differences in grade 3 or 4 non-hematological toxicities. There were no non-relapse deaths during consolidation on the standard arm and 2 in the intensive (0% vs 1%; p =0.50). Subsequently, 41 patients in the standard arm and 37 in the intensive arm underwent elective allogeneic BMT during first remission. On intention to-treat analysis uncensored for transplant and with a median follow-up time of 5.3 years (range 0.6 - 9.9), there was improvement in LFS in the intensive arm compared with the standard arm (3 year LFS 47% (95% CI 40-56%) versus 35% (28-44%); HR 0.74 (95% CI 0.55-0.99); p=0.045) (Figure 1). The 3 year OS for the intensive arm was 61% (95% CI 54-70%) and 50% (95% CI 43-59%) for the standard arm; HR 0.75 (95% CI 0.54-1.05); p=0.092). Although adverse cytogenetics, presence of FLT3-ITD mutation, and absence of NPM1 mutation were all associated with poorer outcomes, there was no evidence of a benefit of intensive consolidation being confined to specific cytogenetic or gene mutation sub-groups. Conclusion: We conclude that in adult patients in complete remission after intensive induction chemotherapy an increased dose of idarubicin delivered during consolidation therapy results in improved LFS, without increased non-hematologic toxicity. Figure 1. Figure 1. Disclosures Szer: Ra Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Alnylam: Honoraria, Membership on an entity's Board of Directors or advisory committees. Marlton:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Wei:Novartis: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; CTI: Consultancy, Honoraria; Abbvie: Honoraria, Research Funding; Servier: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding. Cartwright:ROCHE: Consultancy, Membership on an entity's Board of Directors or advisory committees. Roberts:Servier: Research Funding; Janssen: Research Funding; Genentech: Research Funding; AbbVie: Research Funding. Mills:Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Meeting attendance sponsorship. Gill:Janssen: Membership on an entity's Board of Directors or advisory committees. Seymour:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1344-1344
Author(s):  
Van T. Hoang ◽  
Eike C. Buss ◽  
Isabel Hoffmann ◽  
Abraham Zepeda-Moreno ◽  
Natalia Baran ◽  
...  

Abstract Separation of leukemic stem cells (LSC) and residual hematopoietic stem cells (HSC) from the same individual patient with acute myeloid leukemia (AML) is essential for a proper understanding of the leukemic driving mechanisms. We have studied the role of aldehyde dehydrogenase (ALDH) for this purpose and have defined the functional properties of ALDHbright cells in specific subgroups of AML. We have examined the ALDH activity by flow cytometry in bone marrow samples (BM) from 14 healthy donors and 73 patients with de novo AML. The median frequency of cells with high ALDH activity (ALDHbright cells) in the healthy subjects was 1.92% with a range from 0.58 to 3.16%. For patients with AML, the median number of ALDHbright cells was 0.25% with a broad range from 0.004 to 33.57%. Whereas the majority of patients with AML (n = 56) had low frequencies of ALDHbright cells (median 0.11%; range 0.004 – 1.77%; defined as ALDH-low AML), 17 patients had relatively numerous ALDHbright cells (median 9.01; range 3.54 – 33.57%; defined as ALDH-numerous AML). In both groups, ALDHbright cell populations were highly enriched for CD34+CD38- cells. The ALDHbright cells derived from ALDH-low AML did not contain chromosomal and molecular aberrations characteristic of the original leukemia, and were able to induce multi-lineage hematopoiesis in NSG mouse models. Thus, genetically and functionally normal HSC could be successfully isolated in the ALDHbright subset, whereas LSC were enriched in ALDHdimCD34+CD38- subset for patients with ALDH-low AML. For 17 patients with ALDH-numerous AML, the ALDHbright subset was consistently contaminated with LSC. In clinical follow-ups, patients with ALDH-numerous AML showed resistance to induction chemotherapy and were characterized by a very poor long-term outcome that was comparable to patients with high-risk cytogenetic or molecular genetic markers. In four patients with ALDH-numerous AML we demonstrated that the ALDHbrightCD34+CD38- subset contained chemotherapy-resistant clones with repopulating ability. Furthermore, such ALDHbright cells were characterized by a lower cell-cycle activity and an increased resistance to cytarabine in comparison with ALDHdim blasts in in vitro assays. Our data have provided evidence that LSC and residual HSC can be separated using ALDH in patients with low frequencies of ALDHbright cells. In patients with ALDH-numerous AML, the ALDHbright subset is associated with leukemic features both in vitro and in animal models. Thus our data demonstrated the feasibility of appropriate comparisons of LSC versus HSC from the same patient with specific subtypes of AML and the impact of LSC properties on clinical outcome. Disclosures: Buss: Novartis: Travel support Other; Micromet/Amgen: Reimbursements for participation in a clinical study , Reimbursements for participation in a clinical study Other. Ho:Sanofi-Aventis: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Genzyme: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2292-2292
Author(s):  
Virginia Olivia Volpe ◽  
Akriti G Jain ◽  
Onyee Chan ◽  
Eric Padron ◽  
David A. Sallman ◽  
...  

Abstract Background: Venetoclax plus hypomethylating agents (HMA) (HMA+VEN) is a standard of care treatment for patients with acute myeloid leukemia (AML) who are unfit for intensive chemotherapy. In the phase 3 VIALE-A trial, azacididine (aza)+VEN compared to aza alone demonstrated an improved overall survival of 14.7 months versus 9.6 months, respectively. A common toxicity with HMA+VEN is myelosuppression. The prognostic implications of incomplete count recovery despite leukemia free state after HMA+VEN treatment in AML is unclear. We aimed to compare the outcomes of those who achieved complete remission (CR), complete remission with incomplete hematologic recovery (CRi), or morphologic leukemia-free state (MLFS) in AML patients treated frontline with HMA+VEN. Methods: Patients seen at Moffitt Cancer Center between 2019 and 2021 diagnosed with AML and treated with frontline HMA+VEN were retrospectively evaluated and included for analysis. Patients were stratified by best response; either CR, CRi, or MLFS. Baseline characteristics were compared by chi square (categorical variables) and t- test (continuous variables). Survival estimates were calculated using the Kaplan-Meier method from date of diagnosis and groups were compared using log-rank test. Results: Of the 102 patients treated with HMA+VEN in the frontline setting, 48% (n=49) had blast clearance with a best response of CR in 27/102 (26.4%), CRi in 16/102 (15.7%), or MLFS in 6/102 (5.9%). The remainder had residual disease. Baseline characteristics were similar among the three response groups (Table 1) as was mutational distribution (Table 2). There was no difference between AML WHO classification subtype (p= .148). Decitabine or aza was used at the discretion of the treating physician did not significantly impact responses (p= .225). In those who achieved CR, 14% had prior therapy related AML compared to 37.5% in CRi and 33.3% in MLFS (p= .314). Antecedent MDS or MPN with transformation to AML was seen in 22.2%, 18.8%, and 66.7% of CR, CRi, and MLFS respectively (p= .029). Of those, 3.7% in CR group had HMA use for prior MDS/MPN compared to 0% in CRi and 50% in MLFS (p= .000). The median relapse free survival was not reached for CR, CRi, and MLFS (Figure 1), it is important to note that 3 of the 6 MLFS patients died without relapse . At median follow up of 23 months, median overall survival (OS) in the CR group was significantly longer, 31 months, compared to 18 months in the CRi group and 8.5 months in the MLFS group (p=0.0415) (Figure 2). Transplant was achieved in 26% of CR and 6.3% of CRi and 0% of MLFS and was not significant among the groups (p = .124). Conclusion: Patients who received frontline HMA+VEN for AML directed therapy and achieved CR/CRi had better survival compared to those who achieved MLFS. Our data suggest that incomplete recovery of blood counts plays a significant role in overall survival regardless of leukemia free state. Further, the data demonstrate significantly higher secondary AML with antecedent MDS or MPN in the MLFS group compared to CR and CRi groups. Of those, prior HMA therapy was also identified as significantly higher in the MLFS group compared to CR and CRi groups which may contribute to the prolonged cytopenias and worse OS. While the limitation to this study is overall small number of patients, it suggests that a goal of CR over CRi or MLFS is desirable for superior OS. In the future, it would be of interest to incorporate the rates of responses and variables that may have an impact such as therapy dose adjustment, time to response, and delays in therapy due to cytopenia. Additional studies identifying dose adjustments or other ways to improve hematologic recovery would be valuable to potentially improve outcomes in this difficult to treat population. Figure 1 Figure 1. Disclosures Padron: Stemline: Honoraria; Taiho: Honoraria; BMS: Research Funding; Incyte: Research Funding; Blueprint: Honoraria; Kura: Research Funding. Sallman: Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy; Shattuck Labs: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Incyte: Speakers Bureau; Intellia: Membership on an entity's Board of Directors or advisory committees; Aprea: Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Membership on an entity's Board of Directors or advisory committees; Syndax: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Magenta: Consultancy; Kite: Membership on an entity's Board of Directors or advisory committees. Komrokji: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy; Acceleron: Consultancy; Jazz: Consultancy, Speakers Bureau; Geron: Consultancy; BMSCelgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Taiho Oncology: Membership on an entity's Board of Directors or advisory committees; PharmaEssentia: Membership on an entity's Board of Directors or advisory committees. Lancet: AbbVie: Consultancy; Astellas: Consultancy; Jazz: Consultancy; Agios: Consultancy; Millenium Pharma/Takeda: Consultancy; ElevateBio Management: Consultancy; Daiichi Sankyo: Consultancy; Celgene/BMS: Consultancy; BerGenBio: Consultancy. Sweet: AROG: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol Meyers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3298-3298
Author(s):  
Lili Feng ◽  
Haohai Zhang ◽  
Paola de Andrade Mello ◽  
Dina Stroopinsky ◽  
Wenda Gao ◽  
...  

Abstract Corresponding author: Dr. Simon. C. Robson ([email protected]). Introduction: CD39/ENTPD1 (ectonucleoside triphosphate diphosphohydrolase-1) is the prototypic member of the GDA1-CD39 superfamily of ectonucleotidases and modulates purinergic signaling pathways. CD39 expression has been noted in human acute myeloid leukemia (AML) and likely contributes to chemoresistance [1]. Our study reported here elucidates the impact of Cd39 on engraftment and invasiveness of AML TIB-49 cells using an immunocompetent murine experimental model. Methods: Wild-type (WT) mice and Cd39 -/- mice on C57BL/6 background were bred at Beth Israel Deaconess Medical Center. The syngeneic murine AML cell line TIB-49 (Cd39 negative in vitro) was purchased from American Type Culture Collection. For bioluminescence imaging experiments, TIB-49 cells were transduced with luciferase/mCherry using a lentiviral vector. For AML model, mice were administered with 1×10 6 TIB-49-luciferase cells intravenously via tail vein injection. For chloroma model, mice were subcutaneously inoculated with 1×10 6 TIB-49 cells in the right flank. Bioluminescence imaging of TIB-49-luciferase bearing mice was conducted with the IVIS TM 50 Imaging System. Blood, spleen and bone marrow (BM) were also collected from TIB-49 bearing AML mice for FACS (fluorescence activated cell sorting) analysis. To explore Cd39 in TIB engraftment and invasiveness, TIB-49 cells were further transduced with a lentiviral vector overexpressing mCd39 with TdTomato. WT mice were intravenously inoculated with 1×10 6 of either TIB-49-TdTomato cells or TIB-49-mCd39-TdTomato cells, and the above read-outs were determined. To investigate the potential of CD39 as a therapeutic target, we engineered anti-mouse Cd39 antibodies (αCd39 mAb) with isotype selection and removal of fucose to further promote Fc receptor (FcR) interactions. Results: Bioluminescence imaging results indicated that TIB-49 engraftment was decreased in global Cd39 -/- mice with decreased disease burdens noted relative to WT (Figure 1A). FACS analysis of blood, spleen and BM-derived cells from TIB-49 bearing AML-model mice (day 31) confirmed higher engraftment of TIB-49 cells (TdTomato+) at all sites in WT compared to Cd39 -/- mice (Figure 1B). TIB-49 cells did not express Cd39 in vitro, but TIB-49 cells harvested from spleen and BM of WT but not Cd39 -/- mice displayed high levels of Cd39. This indicated TIB-49 cells acquired Cd39 from host cells, in a process of antibody-independent trogocytosis (Figure 1C), as RT-PCR did not detect Cd39 mRNA expression in TIB-49 cells in vivo. Additionally, circulating TIB-49 cells from the blood of WT mice were Cd39 negative (Figure 1C), suggesting a role for the tumor microenvironment in mediating trogocytosis. TIB-49 cells expressing host Cd39 in WT mice spleen and BM lost Cd39 after being exposed to αCd39 mAb treatment. Cd39 translocated from TIB-49 cells to effector cells, at least in part, dependent on FcR mediated trogocytosis (Figure 1D). When Cd39 was overexpressed on TIB-49 cells (TIB-49-mCd39-TdTomato), the engraftment was boosted in WT mice in vivo when compared to TIB-49-TdTomato cells (day 19, Figure 1E) with higher levels of Cd39 expression than that observed on TIB-49-TdTomato cells in spleen and BM (day 26) (Figure 1F). Moreover, TIB-49-mCd39-TdTomato bearing mice displayed shorter survival times, when compared with TIB-49-TdTomato bearing AML mice (Figure 1G). The αCd39 mAb monotherapy had no effect on TIB-49 chloroma model growth. However, pretreatment with αCd39 mAb effectively boosted daunorubicin chemotherapeutic effects in vivo (Figure 1H and 1I). Conclusions: Our study suggests bidirectional trogocytosis between TIB-49 AML and host immune cells, which is further modulated by FcR interaction. Re-distribution of Cd39 from host to TIB-49 cells or induced high level expression contributes to engraftment and invasiveness, resulting in decreased survival. Targeting CD39 is a potential therapeutic approach, operational not only by boosting chemosensitivity but furthering anti-leukemic effects in experimental models. Disclosures: No relevant conflicts of interest to declare. References: [1] Nesrine Aroua, Emeline Boet, Margherita Ghisi, et al. Extracellular ATP and CD39 Activate cAMP-Mediated Mitochondrial Stress Response to Promote Cytarabine Resistance in Acute Myeloid Leukemia. Cancer Discov. 2020. Figure 1 Figure 1. Disclosures Stroopinsky: The Blackstone Group: Consultancy. Avigan: Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Kite Pharma: Consultancy, Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees; Partner Tx: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Aviv MedTech Ltd: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Legend Biotech: Membership on an entity's Board of Directors or advisory committees; Chugai: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Parexcel: Consultancy; Takeda: Consultancy; Sanofi: Consultancy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3895-3895
Author(s):  
Hannah Asghari ◽  
Dasom Lee ◽  
Yehuda E. Deutsch ◽  
Onyee Chan ◽  
Najla Al Ali ◽  
...  

Background The therapeutic landscape for acute myeloid leukemia (AML) has become complex with recent drug approvals. CPX-351 has become standard-of-care for patients (pts) with therapy-related AML and AML with myelodysplasia-related changes. Moreover, earlier phase studies combining hypomethylating agents (HMA) and Venetoclax (HMA+Ven) in the frontline setting for elderly patients have demonstrated high response rates and improved survival. Given the overlapping indications, yet lack of comparative outcome data between these therapeutic regimens, treatment decisions have become challenging in the frontline setting. Therefore, we compared the outcomes of newly diagnosed AML pts receiving HMA+Ven vs. CPX-351. Methods We retrospectively annotated 119 pts that received frontline treatment with HMA+Ven and CPX-351 at Moffitt Cancer Center and Memorial Healthcare System between 2013 and 2019. Pts were divided in two cohorts: HMA+Ven (Cohort A) or CPX-351(Cohort B). Via comprehensive chart review of each patient that received HMA+Ven, we further classified a subgroup of pts meeting criteria to receive CPX-351 as CPX-351eligible. Clinical and molecular data were abstracted for each patient in accordance with IRB requirements. Overall response rate (ORR) was the combined total of complete remission (CR), complete remission with incomplete count recovery (CRi), and morphologic leukemia free state (MLFS). Fisher's Exact method was used to determine significance. Kaplan-Meier analysis was performed to estimate median overall survival (mOS) with log-rank test to determine significance. All p-values are two-sided. Results Out of 119 total pts, 41 pts received HMA+Ven (Cohort A) and 78 pts received CPX-351 (Cohort B) with baseline characteristics outlined in Table 1. Among 111 response evaluable pts, ORR was 64.1% in Cohort A, including 28.2% with CR and 28.2% with CRi (Table 2). ORR was 50.0% in Cohort B, comprised of CR in 29.2% and CRi in 18.1%. There was no difference in ORR between Cohort A and Cohort B (64.1% vs. 50%, p 0.17). A significantly greater fraction of pts in Cohort B underwent allogeneic stem cell transplant (allo-SCT) (24.4% vs. 2.4%, p=0.004). ORR was higher in pts with European LeukemiaNet (ELN)-defined favorable/intermediate (fav/int) risk compared to adverse risk group in Cohort A (100% vs. 58.3%, p=0.03), however there was no difference in Cohort B (52.6% vs. 49.1%, p=1.0). ORR was similar among adverse risk groups in both cohorts (58.3% in Cohort A vs. 49.1% in Cohort B, p=0.47). Among responders, median time to best response was significantly longer in Cohort A (61.0 days vs. 40.5 days, p<0.0001). Median duration of response was not reached (NR) in both cohorts. Impact of somatic mutations on ORR is represented in Figure 3. Median follow-up was 6.5 months (mo) in Cohort A and 13.0mo in Cohort B. Median OS was similar in both cohorts (A vs. B, 13.8mo vs. 11.1mo, p=0.82) (Figure 1). Among responders, mOS was NR in Cohort A and 18.2mo in Cohort B (p=0.88) (Figure 2). Compared to Cohort B, mOS was superior for pts with fav/int risk disease in Cohort A (14.2mo (B) vs. NR (A), p=0.045) and not different for adverse risk group (11.1mo (B) vs. 7.3mo (A), p=0.2). Prior HMA exposure was 26.8% in Cohort A and 29.5% in Cohort B for an antecedent hematologic malignancy, however it did not impact mOS (p=0.86) or ORR (p=0.7). Early mortality rates for Cohort A and B were similar at day 30 (2.4% vs. 0%) and day 60 (4.9% vs. 3.8%). Rate of relapse was similar between cohorts A and B (16.0% vs. 30.6%, p=0.24). We then compared the outcomes of pts in Cohort B to CPX-351eligible arm from Cohort A (n=14). ORR and mOS were similar in Cohort B and CPX-351 eligible arm (ORR: 50% vs. 50%, p=1.0; mOS 11.1mo vs. 13.8mo, p=0.43). Only 1 patient (7.1%) of the CPX-351eligible arm underwent allo-SCT. Conclusion Our study demonstrates that HMA+Ven results in comparable response rates and survival outcomes to patients receiving CPX-351 when used as an initial remission therapy for patients with newly diagnosed AML, however the median follow up for patients receiving HMA+Ven was short. Survival did not appear to be impacted by a significantly greater proportion of patients proceeding to allo-SCT in the CPX-351 arm. Overall, HMA+Ven may represent a reasonable frontline remission therapeutic choice in patients with AML and a randomized trial would seem justified. Disclosures Kuykendall: Abbvie: Honoraria; Janssen: Consultancy; Incyte: Honoraria, Speakers Bureau; Celgene: Honoraria. List:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lancet:Pfizer: Consultancy, Research Funding; Agios, Biopath, Biosight, Boehringer Inglheim, Celator, Celgene, Janssen, Jazz Pharmaceuticals, Karyopharm, Novartis: Consultancy; Daiichi Sankyo: Consultancy, Other: fees for non-CME/CE services . Sallman:Celyad: Membership on an entity's Board of Directors or advisory committees. Komrokji:celgene: Consultancy; Agios: Consultancy; pfizer: Consultancy; DSI: Consultancy; JAZZ: Speakers Bureau; JAZZ: Consultancy; Novartis: Speakers Bureau; Incyte: Consultancy. Sweet:Abbvie: Membership on an entity's Board of Directors or advisory committees; Stemline: Consultancy; Agios: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Incyte: Research Funding; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Consultancy; Celgene: Speakers Bureau; Jazz: Speakers Bureau. Talati:Agios: Honoraria; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Celgene: Honoraria; Daiichi-Sankyo: Honoraria; Astellas: Honoraria, Speakers Bureau; Pfizer: Honoraria.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2625-2625
Author(s):  
Rasoul Pourebrahim ◽  
Peter P. Ruvolo ◽  
Steven M. Kornblau ◽  
Carlos E. Bueso-Ramos ◽  
Michael Andreeff

Abstract Acute myeloid leukemia (AML) is a genetically heterogeneous malignancy characterized by bone marrow infiltration of abnormally proliferating leukemic blasts which results in fatal anemia, bleeding and infectious complications due to compromised normal hematopoiesis. Patients with complete remission (CR) but incomplete blood cell count recovery (CRi) have significantly shorter survival compared to CR patients. Although there is a correlation between CRi and minimal residual disease (MRD), the two variables were shown to be independent risk factors for relapse development (1). The mechanism by which AML induces bone marrow failure in patients is largely unknown. Here, we demonstrate that AML derived MSCs highly express p53 and p21 proteins and are more senescent compared to their normal age-matched controls as demonstrated by high β-galactosidase staining (figure 1. A, B&C). Emerging evidence indicates that the aging of endosteal niche cells results in lower reconstitution potential of hematopoietic stem cells (2). To functionally evaluate the effects of AML on bone marrow MSCs, we utilized a murine leukemia model of the AML microenvironment. We transplanted Osx-Cre;mTmG mice with AML cells and compared the senescence of MSCs in normal bone marrow (Figure 1.D) with AML (Figure 1.E). Consistent with our initial findings in human, AML strongly induced senescence of osteoblasts. This suggests that AML suppresses normal hematopoiesis by inducing senescence in the hematopoietic niche. To address the role of p53 signaling in senescence of MSCs we generated a traceable conditional p53 gain/loss model specifically in bone marrow MSCs using Osx-Cre;mTmG; Mdm2fl/+ and Osx-Cre;mTmG;p53fl/fl mice respectively (Figure 1.F). Deletion of p53 in bone marrow MSCs resulted in an increased population of osteoblasts (GFP+) in Osx-Cre;mTmG;p53fl/fl mice in comparison to Osx-Cre;mTmG mice suggesting that p53 loss in osteoblasts inhibits senescence of osteoblasts. In order to evaluate p53 activity after recombination of p53fl alleles in the osteoblasts, we isolated MSCs from bone marrows and analyzed the expression of p21.P21 was significantly down regulated in osteoblasts (GFP+) derived from Osx-Cre;mTmG;p53fl/fl mice whereas its expression in the hematopoietic cells from same tissue (tdTomato+) remained comparable to p53 wild type suggesting that p21 as the master regulator of senescence is regulated by p53 in bone marrow mesenchymal cells. To evaluate the effect of p53 loss in osteoblasts and its impact on hematopoietic cells, we isolated the GFP+ cells (osteoblasts) and RFP + cells (hematopoietic) by FACS. Senescent cells, non-cell autonomously, modulate the bone marrow microenvironment through the senescence-associated secretory phenotype (SASP). We analyzed the expression of fifteen SASP cytokines by QPCR. Deletion of p53 in bone marrow mesenchymal cells strongly abrogated the expression of several SASP cytokines. Interestingly several Notch target genes such as Hey1 and Hey2 were highly induced in MSCs following p53 deletion suggesting a role for Notch signaling in hematopoietic failure following AML induced MSCs senescence. Our data suggest that AML induces senescence of endosteal niche resulting in hematopoietic failure. These findings contribute to our understanding of the role of p53 in leukemia MSCs and could have broad translational significance for the treatment of hematopoietic failure in patients with AML.Chen X, et al. (2015) Relation of clinical response and minimal residual disease and their prognostic impact on outcome in acute myeloid leukemia. J Clin Oncol 33(11):1258-1264.Li J, et al. (2018) Murine hematopoietic stem cell reconstitution potential is maintained by osteopontin during aging. Sci Rep 8(1):2833. Disclosures Andreeff: Astra Zeneca: Research Funding; Daiichi-Sankyo: Consultancy, Patents & Royalties: MDM2 inhibitor activity patent, Research Funding; United Therapeutics: Patents & Royalties: GD2 inhibition in breast cancer ; Celgene: Consultancy; Eutropics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Research Funding; Oncoceutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; SentiBio: Equity Ownership; Aptose: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Oncolyze: Equity Ownership; Jazz Pharma: Consultancy; Reata: Equity Ownership.


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